Pecan tree named ‘Seneca’

ABSTRACT

A new and distinct variety of pecan tree, denominated ‘Seneca’, having a compact tree shape that is late to break bud in the spring, ceases growth early in the autumn, a determinate pattern of growth that is freeze tolerant, early season production of high-quality nuts, cream-colored kernels, and pecan scab fungus ( Venturia effusa ) disease resistance.

Latin name of the genus and species of the plant claimed: ‘Seneca’ is a pecan tree that is a Carya illinoinensis.

Variety denomination: The new pecan tree is of the variety denominated ‘Seneca’.

BACKGROUND OF THE NEW PLANT

‘Seneca’, tested as 1997-34-0017, is a 1997 progeny of a cross between two pecan varieties of northern origin, ‘NC-2B’ (seed parent) and ‘NC-4’ (pollen parent) (both unpatented), in Burleson County, Tex. ‘NC-2B’ and ‘NC-4’ are seedling selections obtained from Ontario, Canada. Genomic tests indicate ‘NC-4’ is a cross between ‘Colby’ (unpatented), an Illinois native pecan, and ‘Peruque’ (unpatented), a native pecan from Missouri. ‘NC-2B’ is a ‘Colby’ seedling. ‘Seneca’ was grown in Somerville, Tex. and was selected for further testing for its regular, early season production of high-quality nuts from compact, sturdy, disease-resistant trees suitable for northern pecan growing regions. ‘Seneca’ has been evaluated most extensively in orchards in Brownwood, Tex. in a test that comprised 49 selections with 3 control varieties (‘Wichita’, ‘Pawnee’, and ‘Kanza’) (all unpatented). All trees in this block had between 5 to 6 replicate grafted clones.

SUMMARY OF THE INVENTION

‘Seneca’ is distinguished from other pecan varieties due to the following unique combination of characteristics: a compact, sturdy tree that is late to break bud in the spring, ceases growth early in the autumn, a determinate pattern of growth that is freeze tolerant, early season production of high-quality nuts, cream-colored kernels, and pecan scab fungus (Venturia effusa) disease resistance. However, ‘Seneca’ has only been monitored in Central Texas and has not been observed under all environmental conditions and cultural practices. Therefore, some characteristics may differ outside of Central Texas or with different management practices.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings include color photographs that are as nearly true as it is reasonably possible to make in a color illustration of this type:

FIG. 1 is a chart showing the pedigree of ‘Seneca’. Upper branch depicts the known ancestry of the seed parent (‘NC-2B’). The lower branch depicts the known ancestry of the pollen parent (‘NC-4’).

FIG. 2 is a photograph showing the bark texture of ‘Seneca’ at 15 years after grafting. Photo taken in Brownwood, Tex. on Apr. 7, 2021.

FIG. 3 is a photograph of the leaf architecture of ‘Seneca’ at 15 years after grafting. Photo taken in Brownwood, Tex. on Jun. 4, 2021.

FIG. 4 is a photograph of a red ‘Seneca’ pistillate flower. Photo taken in Brownwood, Tex. on May 13, 2021.

FIG. 5 is a photograph of a ‘Seneca’ nut quality panel. Photo taken in Brownwood, Tex. on Dec. 1, 2015.

FIG. 6 is a photograph of ‘Seneca’ nut clusters. Photo taken in Brownwood, Tex. on Aug. 20, 2018.

FIG. 7 is a photograph of the canopy structure of a 9-year-old ‘Seneca’ tree on an ‘Apache’ (unpatented) seedling rootstock. Photo taken in Brownwood, Tex. on Oct. 5, 2016.

Due to photographical light, chemical development, processing and printing, the leaves and fruit depicted in these photographs may or may not be accurate when compared to the actual botanical specimen.

DETAILED BOTANICAL DESCRIPTION

All color descriptions are based on of the Munsell Plant Tissue Color Book: 2012 Year Revision (2019 Printing).

The botanical description below is based on five grafted clones of ‘Seneca’ located in the same orchard in Brownwood, Tex. In addition, the ortet for ‘Seneca’ is grafted into the canopy of one tree in Burleson County, Tex. Unless otherwise noted, the observations below were collected from April-June in 2021 (15 years after grafting).

-   Parentage:     -   -   Seed parent.—‘NC-2B’.         -   Pollen parent.—‘NC-4’. -   Tree:     -   -   a. Overall shape.—General shape and height to width ratio:             average 1.11. Tree shape is compact, with a slightly narrow             canopy.         -   b. Vigor.—Vigorous. ‘Seneca’ was fruiting 3 years after             grafting.         -   c. Height.—Average Height: 10.65 m.         -   d. Width/trunk diameter.—i. Canopy Width: 9.7 m. ii. Trunk             Diameter: 286 mm.         -   e. Trunk bark texture.—Scaly when Mature.         -   f. Trunk bark color.—Grey-Brown — 2.5Y 5/2.         -   g. Branch color.—i. Woody stage branch shoots: Grey-Brown —             2.5Y 5/2. ii. Lenticels: Lenticel shape is highly variable.             An average length would be 1.36 mm. The average width would             be 1.06 mm. iii. Lenticel Color: Light Brown — 7.5YR 5/8.         -   h. Internodes.—The average length between the 3^(rd) and             4^(th) leaf from the base of the shoot is 14.67 mm.         -   i. Disease and insect resistance.—i. Pecan Scab, Venturia             effusa (leaf and nut), data from 2010-2012, 2015, and 2016.             In our unsprayed orchards, ‘Seneca’ has had only trace             amounts of either leaf or nut scab.         -   j. Leaves (data from June 2020).—i. Leaf Arrangement and             Color. 1. Leaves are odd-pinnately compound opposite. 2.             Upper leaf color is Dark Forest Green — 7.5GY 3/4. 3. Lower             leaf color is Green — 7.5GY 5/4. ii. The number of leaves             per shoot and the number of leaflets per mature leaf. 1.             Leaves per shoot: 5-10, Average 8. 2. Leaflets per leaf:             11-20, Average 16. iii. The angle of leaflet pairs to the             rachis: 45°. iv. Leaflet blade: flat and not convoluted. v.             Length and width of a mature leaf (4^(th) leaf from the base             of the shoot). 1. Length Range: 430-560 mm. Average:             495 mm. 2. Width Range: 275-385 mm. Average: 321 mm. vi.             Petiole shape and color. Petiole shape is circular. Petiole             color is Green-Yellow — 5GY 5/6. vii. Petiole length of the             4^(th) leaf from the base. 1. Length Range: 35.3-66.6 mm.             Average: 53.1 mm. 2. Width Range: 2.3-3.33 mm. Average:             2.73 mm. viii. Leaflet size and shape (4^(th) leaflet on             4^(th) leaf). 1. Leaflet Size Range: 110-180 mm. Average:             146.5 mm. 2. Width Size Range: 31-48 mm. Average:             37.7 mm. 3. Leaflet shape is falcate with serrate margins,             an oblique base, and an acuminate tip. ix. Texture of upper             leaf. The leaf texture is smooth on both the upper and lower             surfaces with a glossy sheen. x. Sheen: glossy. xi.             Petiolule. 1. Petiolule Length Range: 1.74-9.2 mm. Average:             5.32 mm. 2. Petiolule Width Range: 0.8-2.07 mm. Average:             1.27 mm. xii. Margin: Leaf margin is serrate. xiii. Tip             Shape: Leaf tip is acuminate. xiv. Pubescence (Upper leaf             and Lower leaf). Leaf pubescence is mostly glabrous with             occasional pilose regions. -   Inflorescence:     -   -   a. General description.—‘Seneca’ is monoecious,             anemophilous, and protandrous (Table 1).         -   b. Flowers.—i. The number of pistillate flowers and             arrangement of the flowers. 4-7 individual pistillate             flowers per pedicel spike are borne alternately on             terminally positioned spikes. ii. Description of the             pistillate flower and pedicels. Mid-to-late pistil             receptivity with red stigmas. iii. Staminate catkin length             and width (in mm). 1. Catkin Length Range: 62-133 mm.             Average: 97.6 mm. 2. Catkin Width Range: 5-8 mm. Average:             6.5 mm. iv. Staminate color, pollen color. 1. Staminate             color: Golden — 2.5GY 6/10. 2. Pollen color: Yellow — 5Y             8/10. v. Involucre size, including the stigma (length and             width). 1. Involucre Length Range: 6.58-10.67 mm. Involucre             Length Average: 8.42 mm. 2. Involucre Width Range:             1.59-2.22 mm. Involucre Width Average: 1.97 mm. vi.             Description of Anthocyan on stigma. The stigmas are red             sometimes containing patches of green. vii. Flower pistil             color(s). Dominant stigma color is red (5R 3/2) with             occasional splashes of green (5GY 5/6). viii. Number and             color of bracts, shape (lanceolate), flower length and             width, and description of petal fusion and the end resulting             flower shape (copular involucre): Three lanceolate             bracteoles are present and one bract (all green: 5G 4/8).             The bracteoles and bract are fused at the base to form a             copular involucre. -   Fruit:     -   -   a. Mature fruit.—Is dehiscent.         -   b. Shuck.—i. Shuck color is green — 5GY 7/10.         -   c. Fruit split during water stage.—Has not been observed to             be a problem.         -   d. Shuck decline during kernel formation.—Has not been             observed to be a problem. -   Nuts:     -   -   a. Observations are from detailed measurements of five nuts             per year from multiple years.—2009-2018 (except no data in             2013).         -   b. Size.—i. The average nut length is about 37.7 mm. The             average nut width is about 20.9 mm. The length-to-width             ratio is 1.80. ii. Nut cross-section is round with a             flatness ratio (width across sutures to the width between             sutures) of 1.06.         -   c. Form.—i. The shape of the nut with the shape of the             cross-section. The nut is elliptic shaped (length to height             ratio 1.73) with a round cross section. ii. Base shape:             Oblique. iii. Apex shape: Acute. iv. Presence and locations             of defining features: Nut apex is sometimes grooved. v.             Description of shell suture: Often, but not always,             elevated. vi. Description of shell surface: Black lines and             patches stretch from the apex to the midpoint of the nut,             covering up to 50% of the upper nut surface. The lower             10-50% of the nut may be covered with black speckles. vii.             Description of shell topography: Smooth.         -   d. Dorsal grooves.—Kernels have deep, but wide dorsal             grooves that do not trap packing material.         -   e. Ventral grooves.—Kernels have a pronounced ventral groove             that does not trap packing material.         -   f. Weight.—7.36 g (data from 2009-2018, without 2013).         -   g. Cluster size.—On average 2.62 nuts per cluster (data from             2009-2012, 2014, 2016, and 2017).         -   h. Shell topography.—Generally smooth, with a slight ridge             on the suture.         -   i. Shell thickness.—1.22 mm average, moderately thick.         -   j. Shell color.—Brown — 7.5YR 4/4.         -   k. Kernel color.—Cream color: 10YR 7/4.         -   l. Kernel percentage.—57.8% Average.         -   m. Nut maturity date.—September 23^(rd).

COMPARISON TO OTHER VARIETIES

‘Seneca’ is a new pecan cultivar that produces high-quality pecans with attractive, cream kernels on compact disease-resistant trees suitable for the northern growing region. ‘Seneca’ has dark forest green leaves comparable to ‘Pawnee’. Leaflet orientation is similar to most pecan trees, wherein the opposite leaflet pairs are oriented about 45 degrees from the rachis (FIG. 3 ).

‘Seneca’ is protandrous. It has mid-to-late season pollen shed, comparable to ‘Wichita’, and mid-to-late season pistillate receptivity, comparable to ‘Pawnee’ in Brown County, Tex. (Table 1). It usually bears 4-7 alternately-positioned pistillate flowers per pedicel spike. ‘Seneca’ has pistillate flowers with reflexed, red stigmas. It should be a good pollinizer for and be well pollinized by ‘Kanza’ and ‘Lakota’ (unpatented) . On average, spring bud break for ‘Seneca’ was in early April in Brown County, Tex. (91.1 Julian days), around the same time as ‘Pawnee’ (92.3 Julian days) and ‘Kanza’ (89.6 Julian days) and about a week later than ‘Wichita’ (81.8 Julian days) (Table 2). No damage was observed from the prolonged freeze in early February 2021 in Central Texas. ‘Seneca’ exhibited minimal leaf scab fungus (Venturia effusa) susceptibility within our unsprayed orchards in Brownwood, Tex. Its pollen parent ‘NC-4’ showed minimal leaf scab susceptibility and some nut scab susceptibility in a separate orchard in Burleson County, Tex. Within our Brownwood orchard from the years 2010-2012 and 2015, ‘Pawnee’ showed a surprising lack of leaf and nut scab infection, despite nearby ‘Wichita’ trees showing some infection. ‘Seneca’ also displayed minimal infection during those years. From 2015-2017, we observed the expected levels of nut scab infection for the known-susceptible varieties in that orchard while ‘Seneca’ continued to display resistance. The average nut scab observed that period for ‘Seneca’ was only 1.50 percent on the standard area diagram scale of 1 to 100 percent, comparable to ‘Kanza’ at 1.42 percent, with ‘Pawnee’ at 30.89 percent and ‘Wichita’ at 91.51 percent infection (Table 2); indicating a much greater resistance to scab fungus than susceptible control varieties. However, ‘Seneca’ is likely to require fungicide management in more humid environments.

‘Seneca’ produces high-quality nuts, even under limited irrigation, that mature early and are ready to harvest in late September in Central Texas at the same time as ‘Pawnee’. On average, ‘Seneca’ nuts mature around September 23^(rd) (265.5 Julian days) (Table 3). The average nut weight is 7.36 grams for ‘Seneca’, compared to 8.52 g for ‘Pawnee’ and 7.06 for ‘Wichita’. The average number of nuts per pound is 62.92 for ‘Seneca’, compared to 54.63 for ‘Pawnee’ and 67.19 for ‘Wichita’. The pollen parent, ‘NC-4’, produced an average of 63.85 nuts per pound in Burleson County, Tex. ‘Seneca’ has nut dimensions most comparable to ‘Kanza’ among the controls in this test. Nut percent kernel averages 57.38 with a cream color compared to ‘Pawnee’, which has an average 59.14 percent kernel with golden kernels, and ‘Kanza’ which has a 52.83 percent kernel with golden kernels in Brownwood, Tex. (FIG. 5 ). The pollen parent, ‘NC-4’, planted in Burleson County, Tex. has a 54.57 percent kernel with dark golden kernels. ‘Seneca’ averages 2.62 nuts per cluster, compared to 3.28 for ‘Pawnee’, 2.99 for ‘Kanza’, and 3.31 for ‘Wichita’ (Table 3). In the 6^(th) leaf year (2012), ‘Seneca’ bore 12.05 dry weight pounds of nuts, compared to 21.16 for ‘Pawnee’ and 22.05 for ‘Wichita’ (Table 4).

Further detailed information is presented in the tables below:

TABLE 1 Bud break, pollen shedding and stigma receptivity of ‘Seneca’ and other 3 pecan cultivars (control) in the USDA-ARS National Pecan Advanced Clone Testing System (NPACTS) orchard in Brownwood, Texas. 5^(th) 1^(st) 2^(nd) Week Week Week Cultivar Dichogamy Bud Break* April** May May Seneca Protandrous April 1^(st) (91.1 PS PS/PR (type I) days) AB Kanza Protogynous March 31^(st) PR PR PS (type II) (89.6 days) B Pawnee Protandrous April 2^(nd) PS PS PR (type I) (92.3 days) A Wichita Protogynous March 23^(rd) PR PR/PS PS (type II) (81.8 days) C Note: A total of 52 entries (49 breeding lines and 3 cultivars) (grafted onto a rootstock cultivar ‘Apache’ in 2007) were arranged in the NPACTS orchard with a randomized complete block design in 6 blocks in Brownwood, Texas. *Bud break was rated using the following scale: 1 = dormant, 2 = swell, 3 = inner scale split, 4 = burst, 5 = first leaflet expansion, 6 = 25% expansion, 7 = to 50% leaf expansion, 8 = to 75% leaf expansion, 9 = fully expanded leaves. Data is the average of three years records (2016, 2017, and 2021). For comparison, Julian days (in bracket) were calculated when bud break scale reached to scale 3. **PS = Pollen Shedding, PR = Pistillate Receptivity. Values within column followed by a common letter are not significantly different according to Student's t test at p < 0.05.

TABLE 2 Comparison of average leaf and fruit scab susceptibility of ‘Seneca’ and three cultivars (controls) in the USDA-ARS National Pecan Advanced Clone Testing System (NPACTS) orchard (unsprayed) in Brownwood, Texas. Nut Scab Cultivar Leaf Scab* Nut Scab* Percent** Seneca 1.00 B 1.04 B 1.50 C Kanza 1.00 B 1.04 B 1.42 C Pawnee 1.00 B 1.42 B 30.89 B  Wichita 2.71 A 3.49 A 91.5 A *measured with Hunter-Roberts Scale, 1 = no scab, 5 = greater than 50% coverage of leaves or fruit with scab lesions. Data are four years’ average (2010-2012 and 2015). **measured with standard area diagram scale (% of nut with scab lesions) across three years (2015-2017). Values within column followed by a common letter are not significantly different according to Student's t test at p < 0.05.

TABLE 3 Comparison of average nut characteristics of five nuts per tree for four cultivars in Brownwood, TX from 2009-2018 (Wt./nut [g], Nuts/lbs. [no.], Nut length [mm], Nut Length/width, Nut flatness [ratio of nut width across suture to between suture], Kernel [percentage], Nut Maturity Date [75% shuck dehiscence]. Nut sampling was incomplete in 2013. Nut Nut Nut Nut Length Height Width Weight Kernel Cultivar mm mm mm gm Percent Seneca 37.74 B 21.77 C 20.93 C 7.36 B 57.38 B Kanza 34.58 C 22.92 B 21.71 AB 6.61 C 52.83 C Pawnee 41.06 A 23.79 A 21.43 B 8.52 A 59.14 A Wichita 41.23 A 21.97 D 21.97 A 7.06 B 55.58 B 75% Shuck Nut Height Cultivar Nuts Per Lb. Split (Julian Days) to Width Ratio Seneca 62.92 B Sep 23^(rd) (2653) C 1.04 Kanza 69.48 A Sep 28^(th) (270.54) B 1.06 Pawnee 54.63 C Sep 24^(th) (267.01) C 1.11 Wichita 67.19 A Oct 20^(th) (292.74) A 0.96 Values within column followed by a common letter are not significantly different according to Student's t test at p < 0.05.

TABLE 4 Comparison of Dry Weight Nut Yield (average lbs./tree) of five to six replicates of four cultivars growing in one orchard in Brownwood, Texas from 2009-2012. Precocity (years to initial fruiting after nursery transplant) can also be interpreted from this data. These trees were grafted in 2007. Yr. 3 Yr. 4 Yr. 5 Yr. 6 Cultivar 2009 2010 2011 2012 ABI* Seneca — 0.35 0.04 12.05 0.88 Kanza 0.07 0.75 0.44 8.26 0.66 Pawnee 0.18 0.46 0.18 21.16 0.62 Wichita 0.04 0.55 2.09 22.05 0.76 *The alternate bearing index (ABI) is a measure of a cultivar's tendency to produce alternating high and low yields. Ranges are from 0 to 1, with 0 = no alternation and 1 = complete alternation (Pearce and Dobersek-Urbanc, 1967). ABI = 1/(n − 1) × {|(a2 − a1)|/(a2 + a1) + |/(a3 − a2)|/(a3 + 2) . . . + |(an) − a(n − 1))|/(a(n) + a(n − 1))} where n = number of years, and a1, a2, . . . , a(n − 1 ), an = yield of corresponding years. Values within column followed by a common letter are not significantly different according to Student's t test at p < 0.05.

TABLE 5 Comparison of Average Nut Cluster Size (Nuts/ Cluster [no.]) of five to six replicates of four cultivars at Brownwood, Texas from 2009-2017) Yr. 3 Yr. 4 Yr. 5 Yr. 6 Yr. 8 Yr. 10 Yr. 11 Aver- Cultivar 2009 2010 2011 2012 2014 2016 2017 age Seneca 2.50 2.00 1.60 3.69 2.28 — 2.76 2.62 B Kanza 1.47 2.56 2.33 3.23 2.93 4.02 3.02 2.99 A Pawnee — 2.30 1.94 3.93 2.68 4.83 2.67 3.28 A Wichita 2.00 3.23 2.80 3.88 3.10 4.33 3.22 3.31 A Note: No nuts were harvested in 2013 and 2015. Sampling was incomplete in 2016. Values within column followed by a common letter are not significantly different according to Student's t test at p < 0.05. 

We claim:
 1. A new and distinct variety of pecan tree named ‘Seneca’ as illustrated and described herein. 